NSF P248.01 - Military Operations Microbiological Water Purifiers.docx

NSF I

NTERNATIONAL

NSF Protocol P248 Military Operations Microbiological Water Purifiers

The Public

Health and Safety C ompany

TM

February 2012

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NSF Protocol P248 Military Operations Microbiological Water Purifiers

Protocol Developer

Prepared by the U.S. Army Public Health Command [USAPHC, formerly the U.S. Army Center for Health Promotion and Preventive Medicine (USACHPPM)] using a grant received from the Army Study Program Management Office.

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NSF International, in performing its functions in accordance with its objectives, does not assume or undertake to discharge any responsibility of the manufacturer of any other party. The opinions and findings of NSF represent its professional judgment. NSF shall not be responsible to anyone for the use of, or reliance upon this Protocol by anyone. NSF shall not incur any obligations or liability for damages, including consequential damages, arising out of or in connection with the use, interpretation of, or reliance upon this Protocol.

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U.S. ARMY PUBLIC HEALTH COMMAND

ARMY INSTITUTE OF PUBLIC HEALTH

PORTFOLIO, ENVIRONMENTAL HEALTH ENGINEERING

WATER SUPPLY MANAGEMENT PROGRAM

AND

NSF INTERNATIONAL

PROTOCOL FOR EVALUATING THE MICROBIOLOGICAL

TREATMENT CAPABILITIES OF SMALL WATER PURIFIERS

INTENDED FOR USE DURING MILITARY OPERATIONS

February 2012

PREFACE

In the early 2000s, scientists and engineers in the Department of Defense (DOD) identified a mission critical need to assess the performance of commercial off-the-shelf (COTS) individual water purification devices. The military-issued emergency water purifiers in use since the World War II era required multiple time-consuming steps, and could in some cases provide a false sense of security, actually failing to produce potable (microbiologically safe for human consumption) water from available water sources, with no indication that such was the case. The comparatively recent appearance of a multitude of hand-held COTS individual water purifiers (IWPs) was perceived by many to be the remedy to the problem. According to the commercial advertising campaigns, these devices were able to produce microbiologically safe and palatable water from nearly any quality water source, and could keep Warfighters hydrated and missionready when they did not have access to military-provided bulk water supplies. COTS IWPs began to proliferate among deploying units that were able to purchase them with unit charge cards, and among individual deploying Servicemembers who would obtain them at their own expense.

None of the IWPs had undergone rigorous DOD evaluations of their effectiveness and applicability to military missions, nor had they been evaluated and approved by any of the Services’ Surgeon Generals. The primary concern for the lack of military and medical endorsement was for microbiological contaminants – bacteria, viruses, and protozoan cysts – that could rapidly reduce a Warfighter’s mission readiness through acute gastro-intestinal distress or worse. The concern presented an unacceptable risk to deployed personnel in the eyes of the members of the Joint Medical Field Water Subgroup, a subgroup to the Joint Environmental Surveillance Workgroup, which was chartered under DOD Health Affairs. Consequently, a project was initiated to develop a test protocol that all IWPs intended to be marketed to the DOD could be subjected to, to determine their effectiveness in providing microbiological purification. Devices that successfully completed the test protocol could then be used by deployed individuals with a greater measure of assurance that the water they would obtain by using the devices would be of acceptable microbiological quality and would not cause acute illness or disease.

Many current military operations lack the centralized nature of conventional warfare. The transformation to a more agile fighting force where Warfighters inhabit tactical, unit-sized Forward Operating Bases (FOBs), smaller Command Outposts (COPs), and safe-houses, creates unique, never-before-encountered requirements for field water operations and surveillance. These distributed operations have created a gap in fielded materiel for treating water at the unit level (10-50 personnel). Similar to IWP procurement, deploying units have looked to the commercial market to purchase treatment systems [termed small unit water purifiers (SUWPs)] sized between individual purifiers and the U.S. military-fielded Lightweight Water Purifier (LWP), incorporating reverse osmosis and capable of producing 125 gallons per minute from fresh water sources.

This Protocol has been developed with the firm hope that vendors who desire to market their individual or small unit water purification devices to the military will use it to develop, evaluate, and improve their devices. Additionally, it is recommended for use during government downselection and combat development efforts to determine device capabilities. The ultimate goal is to provide our Warfighters the capability to produce sustainable quantities of microbiological contaminant-free drinking water, when necessary, from any fresh-water source that may be available to them during deployments.

The U.S. Army Public Health Command (USAPHC) received a grant from the Army Study Program Management Office to develop this Protocol during FY 2005. USAPHC coordinated closely with personnel from NSF International who provided much guidance and assistance in developing the Protocol and who graciously offered to publish it. USAPHC also solicited and received input from many other DOD organizations, who contributed significantly to the refinement of this Protocol, including the U.S. Navy Environmental Health Center, the U.S. Navy Bureau of Medicine, the U.S. Air Force Institute for Operational Health, the U.S. Air Force 311th Human Systems Wing, the U.S. Army Proponency Office for Preventive Medicine, the U.S. Army Deputy Chief of Staff G-4, DALO-SMT, and the U.S. Army Infantry Center and School. The many efforts of individuals from all of these and other organizations are greatly appreciated

TABLE OF CONTENTS SECTION PAGE

1. INTRODUCTION

1.1 Background

1.2 Equipment Testing Responsibilities

1.3 PSTP Development, Review, and Approval

2. PERFORMANCE REQUIREMENTS

2.1 Microbiological Water Purification

2.2 Operational Capability

2.3 Biocidal Chemicals

3. MICROBIOLOGICAL WATER PURIFIER TEST PROCEDURES

3.1 Purpose

3.2 Apparatus

3.3 Test Water Properties

3.4 Recommended Materials for Adjusting Test Water Characteristics

3.5 Individual Purifier-Specific Test Plan

3.6 Purifier Specific Test Plan - IWP

3.7 Purifier Specific Test Plan - SUWP

3.8 Analytical Procedures

4. MATERIALS

5. DESIGN AND CONSTRUCTION

6. PRODUCT LITERATURE

7. PRODUCT LABELING .............................................................................................. 33 8. AUDITING AND RE-EVALUATION

TABLES

Table 2-1. Microbiological Reduction Requirements Table 3-1. Test Water Constituents for Testing IWPs ......................................................... 11 Table 3-2. IWP Recommended Basic Sampling Plan ......................................................... 14 Table 3-3. SUWP Recommended Basic Sampling Plan

REFERENCES

APPENDICES

A. GLOSSARY OF ABBREVIATIONS AND TERMS

B. GOVERNMENT REVIEW AGENCY (GRA) COMPLIANCE

C. SUGGESTED OUTLINE FOR A PURIFIER-SPECIFIC TEST PLAN

D. ESTIMATION OF THE BACTERIA CONCENTRATION IN

NATURAL WATERS

E. GROWTH CURVE FOR E. COLI AND R. TERRIGENA

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SECTION 1

INTRODUCTION

1.1 BACKGROUND

1.1.1 The need to purify natural waters of unknown or variable microbiological quality is common among members of the military and non-military government agencies, consumer groups, manufacturers, campers, and hikers, as well as others who do not always have ready access to a treated water supply. In response to this need, entrepreneurs and manufacturers have developed a number of small water purifiers [SWPs, to include individual water purifiers (IWPs) and small unit water purifiers (SUWPs)] for campers, hikers and non-government organizations conducting humanitarian assistance operations. Insofar as these devices are intended for military field use, their performance must be thoroughly evaluated to allow informed product selection, and to protect the health of the Warfighters that use them.

1.1.2 This Protocol was derived and adapted primarily from existing publications of the U.S. Environmental Protection Agency (USEPA) and NSF International (references 1, 2 and 3). It describes the procedures to be used to test SWPs designed to achieve reduction or inactivation of microbiological contaminants, including bacteria, viruses, protozoa, and protozoan cysts and oocysts from virtually any fresh water source likely to be encountered by military personnel during exercises and deployments.

1.1.3 Those testing to this Protocol may seek two distinct endorsements. Products may be “certified” by NSF International as having met the requirements of this Protocol and may be granted privilege to use the NSF “mark” when marketing their product. All requirements of this protocol must be met. Contact NSF International for more information. Similarly, execution of this Protocol for acceptance of an SWP for military use will be administered and monitored by a Government Review Agency (GRA) designated by the Department of the Army Office of the Surgeon General. The GRA may grant “compliance” with Appendix B of this Protocol. Those seeking NSF “certification” and GRA “compliance” should convey this request prior to test initiation.

1.1.4 For the purposes of this Protocol, and with reference to their use by deployed military personnel, SWPs for microbiological purification are not intended to significantly reduce chemical contaminants [toxic industrial chemicals (TICs), biological or chemical warfare agents]. Claims made by vendors concerning chemical contaminant reduction efficiencies are not tested and will not be verified by following this Protocol. IWPs tested using this Protocol are intended for individual use during emergency or short term planned missions as an alternative to the currently fielded Globaline® iodine tablets and Chlor-Floc disinfection supplies. SUWPs tested against this protocol may be used during emergency and short term planned missions (less than 7 days), and potentially during long term operations provided produced water quality and field medical oversight follows current doctrine.

Globaline is a registered trademark of Wisconsin Pharmacal Company, Jackson, WI.

Chlor-Floc is a registered trademark of Deatrick & Associates, Inc., Alexandria, VA.

1.1.5 A purifier specific test plan (PSTP) will be developed for each purifier or type of purifier based on this Protocol. The Protocol is intentionally general in nature so as to be applicable to all SWPs, irrespective of physical construction or technology employed. If users find procedures described in this Protocol inappropriate or inapplicable to adequately test their particular purifier or technology, they should describe proposed deviations and document the reasons for modifying or departing from the Protocol in the PSTP. Such deviations and departures will be evaluated by the GRA and judged acceptable as long as the level of testing is not decreased, nor the intent of the Protocol altered. Test conditions and procedures should be designed to specifically challenge the particular technology under evaluation. The testing of SWP performance involves five sequential steps:

(1) development, submission to GRA, and approval of the PSTP

(2) execution of third-party testing in accordance with (IAW) the PSTP

(3) data reduction and analysis

(4) report preparation and information transfer

(5) performance review by GRA and issuance of a Letter of Compliance

1.1.6 Test Sponsors (to include vendors/manufacturers/non-government and government organizations) who’s devices successfully comply with the performance criteria of this Protocol, meet Appendix B requirements, and submit the results to the GRA will receive a GRA P248 Letter of Compliance stating that the device meets the military requirements of NSF Protocol P248, Military Operations Microbiological Water Purifiers. Without the Letter of Compliance test sponsors shall not claim, or market their device as being compliant with Appendix B of this protocol. Information on requirements for GRA compliance can be found in Appendix B.

1.1.7 Application of SWPs intended for individual and group use in non-military operations is within the scope of this Protocol. Organizations may request assistance from the GRA for nonmilitary applications.

1.1.8 Inasmuch as this Protocol was developed subsequent to and is based heavily on the USEPA Guide Standard (reference 1) and NSF Protocol P231 (reference 3), and some vendors of SWPs have already tested their purifiers, either in their own laboratories or by a third-party, using these protocols, those vendors may submit a request to the GRA that a device be “grandfathered” into compliance. On receipt of such a request, together with a copy of the test plan followed and the evaluation and report or results, the GRA will review the documents and determine the equivalency of the tests performed to those required by this Protocol, and at its sole discretion, grant or deny grandfathering. If the GRA grants grandfathering, it will provide the vendor a letter stating that they may claim NSF Protocol P248 compliance for their device(s). In the case of denial, the GRA will issue a written statement to the vendor specifying the reasons for denial, and, in any case, the vendor may retest the purifier(s) using this Protocol and/or appeal the denial with rebuttal and/or additional information for the GRA to reconsider grandfathering as a means of compliance.

1.1.9 To promote consistent, accurate, and comparable results across laboratories, all laboratories performing testing of water treatment equipment for U.S. Military application under NSF Protocol P248 are required to possess / obtain accreditation based on the International Organization for Standardization / International Electrotechnical Commission (ISO/IEC) 17025:2005 (reference 4), by a recognized third party accrediting organization [e.g., American Association for Laboratory Accreditation (A2LA), National Environmental Laboratory Accreditation Program (NELAP), etc.]. All analytical procedures conducted during protocol execution for reporting must be listed on the laboratory’s “Scope of Accreditation”. These requirements also apply to contract laboratories conducting analyses on behalf of the primary testing laboratory. ISO/IEC 17025 is an internationally-accepted standard for developing laboratory management systems for quality, administrative, and technical operations and an accreditation is a crucial requirement for acceptance of test data by the U.S. Military.

1.2 EQUIPMENT TESTING RESPONSIBILITIES

1.2.1 Test Sponsor Responsibilities. The test sponsor is responsible for:

· notifying the GRA of the intent to test equipment using this Protocol

· selecting, negotiating with, and obtaining the concurrence of the GRA for the third-party equipment testing organization (ETO)

· developing the PSTP (with assistance from the ETO)

· submitting the PSTP to the GRA for review and comment

1.2.2 ETO Responsibilities. The ETO is responsible for:

· Providing documentation on accreditation to ISO/IEC 17025 in accordance with section 1.1.8 of this protocol.

· assisting the test sponsor in developing the PSTP and having it approved by the GRA

· coordinating with the GRA to resolve product- and technology-driven modifications to the Protocol

· conducting the testing IAW the GRA-reviewed and approved PSTP

· managing, documenting, evaluating, interpreting, and reporting all test results

· providing a written report documenting the test procedures, deviations from this Protocol, results of testing, and the performance evaluation of the IWP as directed in the PSTP.

· providing quality assurance and documentation as requested by the GRA

1.2.3 GRA Responsibilities. The GRA is responsible for:

· assisting test sponsors and ETOs in interpreting and complying with this Protocol

· assisting test sponsors, if necessary, in identifying and selecting qualified ETOs

1.3 PSTP DEVELOPMENT, REVIEW, AND APPROVAL

1.3.1 The ETO and the test sponsor must adhere to the requirements of this Protocol in developing the PSTP. The final draft PSTP submitted to the GRA for review and approval shall:

· include the information requested in this Protocol

· conform to the format identified herein

· conform to the testing procedures described herein

· include any unique requirements identified by the GRA during initial coordination

1.3.2 Specifically, the PSTP shall include the following essential elements (see Appendix C for a PSTP template):

· the test sponsor’s name and address, and a point-of-contact (POC) name and telephone number

· the name and address of the ETO and a list of designations, recognitions, certifications, etc., that qualify the ETO to perform the testing

· the names, model numbers, and serial numbers of the tested IWPs

· the manufacturer’s operating instructions (as an attachment)

· a description of the roles and responsibilities of the testing participants

· a description of the SWP, the basic technologies it uses, and its advertised capabilities

· A list of materials for all parts that contact water, to include acceptance of materials for contact with drinking water and/or sufficiently detailed material specifications so that a toxicological analysis can be performed.

1.3.3 Once the ETO and the test sponsor have an agreed-upon draft PSTP, it shall be submitted to the GRA for technical review and approval prior to initiation of any testing.

SECTION 2

PERFORMANCE REQUIREMENTS

2.1 MICROBIOLOGICAL WATER PURIFICATION

A SWP must demonstrate the microbiological reduction capabilities described in Table 2-1 when tested according to an approved PSTP developed IAW this Protocol as described in Section 3.

Table 2-1 – Microbiological Reduction Requirements.

Challenge1 Minimum Required Reduction2

1 The influent challenges may constitute greater concentrations than would be anticipated in source waters, but these are necessary to properly test, analyze, and quantitatively determine the indicated log reductions. The influent challenge must not be less than that required to demonstrate the minimum required log reduction. Mathematical rounding is not allowed in determination of overall log reduction. 2 “Reduction” is kill, remove, or inactivate.

2.1.1 Devices that incorporate ultra-violet (UV) light, without additional treatment technologies for pathogen reduction, shall use MS2 bacteriophage at an influent concentration of 5 x 104 to 5 x 105 per L. Testing shall follow NSF/American National Standards Institute (ANSI) Standard 55 collimated beam procedures to measure virus stock susceptibility to UV light and determine the resultant log reduction of MS2 that equates to a dose of 40 mJ/cm2. This log reduction then becomes the reduction requirement for Protocol compliance. UV testing shall incorporate all other applicable requirements of this Protocol. UV devices that do not include a vessel for water during treatment must show pathogen reduction efficacy using the most current and appropriate vessel available to military personnel (e.g., canteen or personal hydration system). Compliance with Protocol requirements, if shown, must state the water vessel used during testing.

2.1.2 Devices that incorporate un-common, or multiple technologies for pathogen reduction/inactivation may require different organisms and/or procedures than described in this Protocol to fully demonstrate device capabilities. Unless it has been shown that one of the listed non-pathogenic surrogates is an acceptable challenge for the given technology, the use of the naturally occurring pathogen is required. The PSTP will provide a forum for the manufacturer to provide specific testing procedures for these technologies to the GRA for approval. NSF Protocol P231 (reference 3) and the USEPA Guide Standard (reference 1) may be consulted for the selection of appropriate organisms and/or procedures to conduct testing.

2.2 OPERATIONAL CAPABILITY

2.2.1 While this Protocol does not presume to dictate the physical characteristics of SWPs that make them useful to or desirable by Warfighters – those characteristics are defined by units, unit commanders, and missions – there are desirable characteristics and operational capabilities that will be considered in the final recommendation as to device suitability for use in various military field operation scenarios.

2.2.2 The characteristics listed below have been selected from current and draft operational requirements documents (reference 5), and are considered desirable, if not required by the U.S. Military. Commanders planning to purchase specific SWPs will consider these or similar criteria and how they relate to the mission for which the SWPs are to be selected in their decisions. Not all of the following are evaluated by this Protocol. The ideal SWP would, in no particular order of importance:

· allow filling and servicing without contaminating the purified water or surfaces that contact the purified water

· be able to be worn with, attached to, or carried on or in current and future load bearing equipment (IWP only)

· be capable of operation by Warfighters in any terrain type and climatic condition (Basic and Hot)

· be fully operational after freeze / thaw cycles

· be compatible with standard 1- and 2-quart canteens and military-approved personal hydration systems

· be easily cleaned and disinfected

· be operable by military personnel of all sizes, strengths, and physical condition

· have a functional life after initial use of at least 120 days (IWP only), and a shelf life of 5 years

· have a treat-to-drink time of less than 20 minutes

· provide an explicit indication or assurance of the unit’s effective use lifetime (in terms of volume purified) to warn the consumer of potential diminished treatment capability through one or more of the following:

· cessation of water flow o a visual change

· simple, explicit instructions for servicing and replacing components within the recommended use life (measurable in terms of volume throughput, specific time frame, or other appropriate method)

· purify at least 135 liters of water as packaged (IWP only)

· reduce water turbidity to less than 1 nephelometric turbidity unit (NTU)

· require little or no training to operate and maintain

· resist mold, fungus, and biofilm growth

· use readily available and easily installed replacement filters and parts

2.3 BIOCIDAL CHEMICALS

2.3.1 Biocidal Chemical Leaching

Where silver or other biocidal chemicals are used in a candidate SWP, the concentrations of those chemicals in the product water must be less than: 1) the corresponding short-term Military Exposure Guidelines (MEG) concentrations in the current edition of USAPHC Technical Guide (TG) 230 (reference 6); 2) the corresponding USEPA National Primary Drinking Water Regulation (NPDWR) maximum contaminant levels (MCL) if there are no MEGs, or otherwise be demonstrated not to constitute a threat to health from consumption or contact if neither MEGs nor MCLs exist.

2.3.2 Stability of Biocidal Chemical

Where biocidal chemicals are used in the treatment unit, the stability of the chemical for disinfectant effectiveness should be sufficient for the potential shelf life and the projected-use life of the unit based on manufacturer’s data. Where stability cannot be assured from historical data and information, additional tests may be required.

SECTION 3

MICROBIOLOGICAL WATER PURIFIER TEST PROCEDURES

3.1 PURPOSE

The candidate SWP is tested to substantiate its microbiological reduction or inactivation capabilities as defined in Table 2-1 over the effective use life of the device and, where a biocidal chemical is used, to determine that said chemical is not present in the effluent at excessive levels.

3.2 APPARATUS

Three production units of each candidate SWP will be tested simultaneously. The units should be new and removed from the commercial packaging just prior to beginning testing or, if appropriate, shall be “reset” with new, production components to perform as new systems in the existing commercial configuration. Manufacturers are welcome to test research and development (R&D) or “Beta” devices against this Protocol, however, GRA involvement, including PSTP and subsequent laboratory data review, will be at its discretion. This does not apply to government-directed testing of R&D devices.

3.3 TEST WATER PROPERTIES

3.3.1 Test waters listed in Table 3-1 are to be used throughout testing. These waters are used to carry the test microorganisms, and should not assist the devices in inactivating the microorganisms. At microbiological sampling points, a deionized water (DI) with a conductivity of less than 2 μS/cm shall be used to prepare the test waters. While it is recommended that DI water be used to prepare all test waters, dechlorinated tap water adjusted to the requirements of Table 3-1 may be used between sample points. No disinfectant of any kind shall be present in any of the test waters prior to treatment. Each device is to be tested using two test waters, the General Test Water, and the appropriate Challenge Test Water. The characteristics of the General Test Water and Challenge Test Waters for devices using halogen disinfectants, filtration, ultra-violet light, and copper / silver disinfectants are shown in Table 3-1. Also shown is a test water to be used without microorganisms to assess the leaching of silver into the treated water from silver-impregnated devices.

3.3.2 For technologies not listed in Table 3-1,the General Test Water should be adequate for the unstressed (General) testing phase. For the stressed (Challenge) testing phase, the test sponsor and ETO must determine what physical and chemical parameters should be used to make up a technology-specific Challenge Test Water that will sufficiently challenge the device to ensure that it provides adequate treatment under stressed conditions. The ETO should provide the Challenge Test Water composition to the GRA as part of the PSTP for review and approval. In addition to test water characteristics, variables such as low battery power, environmental conditions (very hot/cold), and other technology-specific efficiency reducers should be employed in the testing procedures and documented in the report.

Table 3-11 – Test Water Constituents for Testing SWPs.

Halogen Challenge Filter Challenge

UV

Challenge Cu/Ag Challenge Silver (leaching)

Chlorine[footnoteRef:1] (mg/L) [1: All chlorine shall be reduced to below detection limits. Chloride in the test water may interfere with chlorine measurements so analysis shall be conducted on the base water prior to adjustment. ]

5.0 ± 0.2[footnoteRef:2] [2: For iodine based disinfectants the Challenge Test Water phase will be split between pH 5 and pH 9 as described in the PSTP with at least one microbiological challenge point in each pH. ]

Alkalinity5 (mg/L as CaCO3)

Background Bacteria[footnoteRef:3][footnoteRef:4] (cfu/100 mL) [3: Bacteria type chosen from those listed in Table 2-1. Refer to Appendix E for estimation of background concentrations in natural waters. ] [4: Added as buffer, target value - not subject to test rejection if outside range shown ]

≥ 10 ≥ 10 ≥ 10 ≥ 10 ≥ 10

DOC[footnoteRef:5] (mg/L) [5: Analyzed as TOC after filtration through 0.45µm filter. Filter blank must be analyzed to demonstrate organic content attributable to filter. 7 Ultra-violet light transmittance at 254 nm 11 ]

1 Partially assembled from NSF P231; when creating test waters laboratories should target middle of ranges shown.

3.4 RECOMMENDED MATERIALS FOR ADJUSTING TEST WATER CHARACTERISTICS

· pH: inorganic acids or bases (e.g., HCl, NaOH)

· Total Organic Carbon (TOC): tannic acid

· Turbidity: International Organization for Standardization (ISO) specification 12103-A2 fine test dust.

· Total Dissolved Solids (TDS): sodium chloride, Sigma Chemical Co., S9883 (St. Louis, MO), or other equivalent source of TDS

· Alkalinity: sodium bicarbonate

3.5 PURIFIER SPECIFIC TEST PLAN

3.5.1 The following requirements apply to testing of all SWPs. Additional requirements specific to IWPs and SUWPs are provided in subsequent sections.

3.5.2 The test sponsor, together with the ETO, will produce a written, device-specific PSTP and forward it to the GRA for review and comment prior to beginning testing. The test plan should provide for the evaluation of candidate SWP performance under both normal and stressed operating conditions. It is preferred that the PSTP template provided in Appendix D be used to expedite GRA review and be submitted in Microsoft Word to allow for GRA commenting. Specific questions and PSTP submissions should be directed to the USAPHC Water Supply Management Program at (410) 436-3919, water.supply@amedd.army.mil.

3.5.3 The ETO will maintain the specified test water quality throughout each phase of testing (e.g., General or Challenge Phase), not just at sample points. The laboratory will verify the test water composition using analytical procedures at the beginning of each day, or more often if necessary to ensure compliance with Table 3-1. Additionally, test water turbidity, pH, and temperature measurements will be taken at each sample point, and two other times during each day of testing to ensure compliance with the ranges shown in Table 3-1. On non-sampling days, the stated parameters will be measured three times daily (beginning, middle, end). Details on how the test water was prepared and transferred to the devices for processing shall be included in the final report.

3.5.4 Microbiological challenge organisms will be separated into two sequential challenges separated by a 10 void volume seeding. In order to quantify coliphage type they will be applied in separate challenges.

3.5.5 Testing procedures must replicate field use. Water quality and operating conditions during the stress testing phase using the Challenge Test Water should provide the IWP a realistic worstcase challenge.

3.5.6 In general, devices should be tested without any prior conditioning or seasoning with test water or any other water. Should conditioning be required the PSTP must clearly explain the procedures, including conditioning water quality, and conditioning steps must be provided to the user in the supplied device instructions. Conditioning steps must be executable in field environments. Conditioning will use General Test Water, including background bacteria. Conditioning volume does not accumulate against the test volume.

3.5.7 If the SWP can be operated in more than one way, all methods of operation should be evaluated. Alternatively, if one method can be demonstrated to be the most rigorous of the method options, only that method need be used during testing.

3.5.8 If the SWP uses a cleanable element with a finite number of cleanings (e.g., ceramic element), testing must demonstrate that the device meets the microbiological reduction requirements after the element has been cleaned the maximum number of times allowed in the manufacturer’s directions (if applicable).

3.5.9 Challenge solutions containing the microbiological contaminants will be continuously mixed. Influent background bacteria concentrations must be maintained at or above the specified influent concentrations except when the concentrations of all microbial contaminants are increased to the requirements of Table 2-1 at sampling points as described in Section 3.6.4.

3.5.10 Devices that use consumable power sources (e.g., batteries) must incorporate at least one sample point during the final 20% of the power source life. The power source life must be demonstrated during testing. Additionally, treatment systems that incorporate technologies whose effectiveness may vary with time, must treat an amount of water equivalent to the manufacturer-stated capacity of the device or the capacity stated in the PSTP (e.g., a battery operated batch disinfectant device shall be operated sufficient times to treat the entire production capacity stated in the PSTP).

3.5.11 An appropriate sample volume will be retained as a backup for confirmation or retesting purposes when necessary. All pathogens will be analyzed in triplicate with geometric means reported.

3.6 PURIFIER SPECIFIC TEST PLAN – INDIVIDUAL WATER PURIFIER

3.6.1 Devices should generally be operated in batch mode IAW the instructions contained in the commercial package. If continuous-flow testing is preferred by the test sponsor and ETO, the reasoning, proposed plumbing, and test procedures must be specified in the PSTP.

3.6.2 A basic sampling schedule and plan to test the device for short-term use is shown in Table 3-2. Test plans for a specific model may require variations from the plan shown and should be designed to provide worst-case testing.

3.6.3 Minimum test capacity is 135 L unless it can be shown that this is inappropriate for the intended use of the device. Testing should be designed to demonstrate the capacity of the device out to the point where functional component replacement is required.

3.6.4 Prior to each sampling point the device shall be seeded with at least 10 void volumes of test water at the sampling point pathogen concentrations shown in Table 2-1. For ease of testing of batch system, it is recommended that one full batch be used for seeding. At the sampling point a 3 L volume (or full batch, depending on batch size) of sampling point pathogen concentration test water will be processed by the device. The entire processed volume will be collected as the sample and used from which to pull aliquots for individual analyses. For nonbatch systems, sample size will be based on the intended use of the device.

3.6.5 For devices that us a filtration step, the final (100%) sampling point will be collected to document the capabilities of the device at the point of clogging. The final sample will be collected at the point of clogging (at or beyond the 100% projected capacity), represented by the reduction in flow as described in the manufacturer instructions for triggering cleaning or a filter change, or if not stated, a 75% reduction of flow as compared to the Day 1 star-up flow rate.

Table 3-2 – IWP Recommended Basic Sampling Plan.

Test Point:

Percent of Estimated Capacity1

After 48-Hour Rest, First Draw4 Device stored at room temperature following manufacturer’s recommendations. Challenge Test Water, no pathogen challenge

100% Clogging Point6

1 Capacity based on minimum 135 L, as described in paragraph 3.6.5.

2 Treatment Chemical refers to any chemical added to the test water as part of the device’s water treatment process (e.g., chemical disinfectant).

3 Immediately after this sample is collected, test water must change to Challenge Test Water requirements.

4 If stagnation is not appropriate for the device technology, this becomes a standard sampling point.

5 The geometric mean of the three previous influent concentrations will be used to calculate the log reduction after stagnation.

6 The clogging point will be collected in accordance with paragraph 3.6.5.

3.7 PURIFIER SPECIFIC TEST PLAN – SMALL UNIT WATER PURIFIER

3.7.1 The plumbing and recommended points of sampling should be specified in the PSTP.

3.7.2 A basic sampling schedule and plan to test the device for short-term use is shown in Table 3-3. Testing plans for a specific model may require variations from the plan shown in Table 3-3 and should be designed to provide worst-case testing.

3.7.3 The device will be operated for a minimum of 4 hours per day, excluding start-up procedures. Microbial challenges and subsequent sampling will be performed at the end of each sampling day.

3.7.4 Prior to each sampling point the device shall be ”seeded” with at least 10 void volumes, of test water at the elevated microbiological challenge concentrations shown in Table 2-1. At each sampling point sufficient effluent volume for all analyses will be collected as a batch then aliquots drawn for individual analyses.

3.7.5 During the Challenge Test Water phase, the TOC and turbidity of the test water will be increased to meet the requirements of Table 3-1 at sampling points only, including the 10 void volume seeding prior to each sampling point. All other water quality parameters will meet Table 3-1 throughout testing. Seeding volume shall accumulate against the test capacity volume.

3.7.6 For devices that us a filtration step, the final (100%) sampling point will be collected to document the capabilities of the device at the point of clogging. All water beyond 4 hrs of operation on day 10 will contain TOC and turbidity at the challenge values shown in Table 3-1, with the intention of clogging the system. The final sample will be collected at the point of clogging, represented by the reduction in flow as described in the manufacturer instructions for triggering a filter change, or if not stated, a 75% reduction of flow as compared to the Day 1 starup flow rate.

Table 3-3 – SUWP Recommended Basic Sampling Plan.

Chemical[footnoteRef:6] [6: Treatment Chemical refers to any chemical added to the test water as part of the device’s water treatment process (e.g., chemical disinfectant). ]

Microbiological Tests

Day 5[footnoteRef:7] [7: Immediately after this sample is collected, test water must change to Challenge Test Water requirements. ]

General Test Water

turbidity added only at sampling points.

After 48-Hour Rest, First Draw[footnoteRef:8] [8: If stagnation is not appropriate for the device technology, this becomes a standard sampling point. ]

Device stored at room temperature following manufacturer’s recommendations.

Challenge Test Water, no pathogen challenge

Effluent

Day 10 / Clogging Point[footnoteRef:10] [10: The clogging point will be collected in accordance with paragraph 3.7.6.

16 ]

will include TOC and turbidity.

1 Based on 4 hours of flow/day (including start up).

3.8 ANALYTICAL PROCEDURES

3.8.1 General

3.8.1.1 Both treatment chemical (effluent) and microbiological (influent and effluent) sampling and analysis shall be conducted at each test point indicated in Table 3-2 or as specified in the approved PSTP. All physical and chemical analyses shall be conducted IAW procedures in the current version of Standard Methods for the Examination of Water and Wastewater (reference 7) or equivalent.

3.8.1.2 Quality assurance testing shall be conducted for the seed microbes under environmental conditions of the test (pH, turbidity, temperature, TDS and TOC) to make sure that there is no significant change over the test period.

3.8.1.3 When the IWP employs a disinfectant (e.g., halogen or silver), the active agent residual will be measured in the effluent at each microbiological test point. Immediately after collection (allowing for the contact time specified in the manufacturer’s instructions for the product water), each test sample must be treated to neutralize any residual disinfectant. For silver-based disinfectants, thioglycollate-thiosulfate neutralizer solution (reference 8) is appropriate, and for halogens, sodium thiosulfate shall be used. This solution should be prepared daily. All results are invalid unless samples are neutralized, and neutralization is verified, immediately upon collection.

3.8.1.4 In addition to the basic sampling plan, when the devices being tested contain silver, two new devices will be tested using the silver leaching test water. Testing will follow the same testing procedures, but without the microbiological loading, to ensure the silver is not leached into the effluent at concentrations exceeding the short term MEG for silver specified in the current edition of the USAPHC TG 230 (reference 6), or the corresponding USEPA NPDWR MCL if there is no MEG. The sample plan will be based on procedures described in the USEPA Guide Standard (reference 1). If a different bacteriostatic material is used within the device, procedures shall be developed to evaluate leaching of that material.

3.8.2 Microbiological Methods

The following section describes the microorganisms to be used by the ETO to demonstrate the reduction capabilities of the IWP. There are three categories of microorganisms: bacteria, viruses, and protozoa. These microorganisms are representative of the types of microbiological contaminants expected in untreated source waters and to which the SWP might be applied.

3.8.2.1 Selection of Microorganisms

3.8.2.1.1 The microorganisms selected for inclusion in this Protocol are well documented as laboratory test organisms. Some are also pathogenic organisms in and of themselves and, therefore, have an added significance if the SWPs demonstrate successful reduction. They have varying degrees of susceptibility to commonly used drinking water disinfectants. Additionally, the microorganisms represent an array of particle sizes that should provide useful information with respect to SWPs that rely on mechanical size exclusion for the reduction of microbes.

3.8.2.1.2 The bacteria species Raoultella terrigena (R. terrigena, formerly Klebsiella terrigena), Escherichia coli (E. coli), or Bacillus atrophaeus (B. atrophaeus, spore form) may be used to represent the challenge of bacterial contaminants. The ETO will select one of the bacteria species for test purposes. These three bacterial genera, as well as members of the Enterobacteriaceae family, have a history of use in disinfection studies and protocols (references 1, 9 and 10). R. terrigena and E. coli are typical of the total coliform bacteria group frequently found in untreated surface waters. The coliform bacteria levels in many rivers and streams with typical pollution sources have been found to be 105/100 mL or higher. E. coli has added health significance as its presence is very indicative of fecal contamination. Some strains of E. coli produce a strong toxin that can lead to severe gastrointestinal illness. B. atrophaeus, a species of the Bacillus genus, shares many characteristics with Bacillus anthracis, the organism that causes anthrax.

3.8.2.1.3 In the virus category, MS2 and fr bacteriophages or “coliphages” are the viruses recommended for testing of the SWPs. MS2 is a virus that infects E. coli bacteria and has been well documented in literature as a challenge organism for disinfection studies. Enteric viruses are responsible for many waterborne illnesses. Studies have indicated that enteric virus concentrations in typical polluted waters approach 102 per liter of water (reference 1). These phages were chosen as surrogates based on their small size and isoelectric points. fr is 19 nm in diameter with an isoelectric point at pH 8.9, and MS2 is 24 nm in diameter with an isoelectric point at pH 3.9. The small diameter of both of these viruses approximates the size of many of the smaller enteric viruses. The isoelectric point is the pH at which the virus is neutrally charged. The viruses have varying isoelectric points, so they will have different surface charges, or different strengths of negative or positive charge at the different pH values. In solutions with pH above the isoelectric point, the virus will be negatively charged; below it, the virus will be positively charged. fr Phage should be used with MS2 for the viral challenge due to its small size and high isoelectric point. This approach serves to evaluate whether electrostatic forces play a role in virus retention in addition to mechanical filtration.

3.8.2.1.4 Cryptosporidium parvum is a very common protozoan found in the majority of surface water supplies in the U.S. It causes Cryptosporidiosis, a severe gastrointestinal illness. Common disinfection practices used in public water systems are not effective against Cryptosporidium. Therefore, municipal water systems using surface waters are required to reduce Cryptosporidium prior to disinfection, generally by adding or improving filtration operations. In the environment, the organism exists in a protective cyst stage called an oocyst.

Cryptosporidium oocysts are typically 3-5 microns in diameter. For purposes of testing the SWPs, C. parvum is recommended over Giardia lamblia, which was the protozoan used in the USEPA Guide Standard (reference 1). Cryptosporidium oocysts are smaller in size compared to the Giardia cysts (which are 8-10 microns in diameter) and Cryptosporidium is much more disinfectant-resistant than Giardia.

3.8.2.1.5 Bacteria, viruses, and phages can be obtained from the American Type Culture Collection (ATCC), Manassas, VA or an equivalent source. Cryptosporidium may be obtained from Waterborne Inc., New Orleans, LA, Bunch Grass Farms in Idaho, or an equivalent source.